Currently, Base Band Unit (BBU) and Remote Radio Unit (RRU) are employed in some radio base stations. Both the BBU and the RRU comply with the CPRI protocol. The BBU corresponds to a Radio Equipment Control (REC) in the CPRI protocol, and the RRU corresponds to Radio Equipment (RE) in the CPRI protocol. Depending on the application scenario, multiple REs may form a chain, a star, or a ring. An interface between the REC and the RE is known as a CPRI, and a link between the REC and the RE is known as a CPRI link.
If the CPRI link backup mode is applied, two CPRI links exist between the REC and the RE. One CPRI link is set between one port of the REC and one port of the RE, and the other CPRI link is set between the other port of the REC and the other port of the RE. According to the existing CPRI data transmission scheme, one CPRI link is used to transmit user-plane data and control-plane data, and the other CPRI link is used to detect signals to judge whether the link is connected or not.
In the prior art, if the amount of user-plane data is large and is transmitted by only one CPRI link, the CPRI link for transmitting user-plane data may be congested, and even the data may be lost.